Analyst Tells Why He Rebuffed the F.B.I.

One of the figures in the government’s widening investigation of suspected insider trading discusses how he was visited by the Federal Bureau of Investigation. He says he refused to cooperate in the investigation, and he asserts that as a result of having to disclose his involvement, his business “has been destroyed.”

John Kinnucan is the founder of Broadband Research, a technology research firm that includes hedge funds among its clients. He spoke to CNBC about an F.B.I. agent’s efforts to persuade him to cooperate.